You can get a rough idea by watching your monitor page.

It tells you wether an upload was complete or interrupted, but sometimes, only a portion is uploaded from your compter, so the only time you can be positive is when the file size shown matches the file uploaded, AND it says completed.

Default is to clear complete, but you can change that in options. You can clear them manually after studying them.
Good way to monitor what people want, too.

And it makes you feel so warm and fuzzy inside.
Completed.